I have two of these units on a 24" fixture over a 36" tank. I would have bought a 3rd, but my tank has a center brace, and the last expansion slot is centered, so there's no point.

First off, the two multicolor modules that I bought were the only two Vertex items in my order that contained any form of instructions (the light itself and the V-Link has bupkis as far as informational literature), so there's that. However, the circuit boards were packed in a small white cardboard box, and sitting directly on top of a piece of styrofoam packing material. They were not packed in an anti-static bag like they should have been, and there was no desiccant packet enclosed (you know that little package which says "do not eat" you always wonder about? it contains a highly absorbent salt that protects electronics from moisture during shipping). Because of the way the units were packed, there were tiny bits of foam embedded in the circuit that had to be very carefully removed before I felt comfortable installing it.

As far as installation was concerned, the BRS installation video clearly shows a plastic installation bracket being used to position the module, and press it into place. There was no such bracket included with either of my two modules, despite the fact that the instruction slip indicated that it should be present, and was to be used. Instead, I carefully pressed the circuit into place by hand, started each of the screws, and gradually tightened them each a little at a time to seat the boards into place.

Now for the good bit: performance. When I installed the fixtures, the software detected them at once and made them available to the "light studio" interface. You'll need to use the custom mode to get the proper benefit from these modules. You can control each color individually, which is quite nice.

The addition of a small amount of warm white and the two violets to the color spectrum produced by the fixture is a nice touch. They offer the ability to tweak the color output to suit your exact tastes. The UV is invisible, of course, but I guess there's enough evidence to suggest that it's worth while having them around.

Alas, the red and green are not all they're cracked up to be. Because of the fact that their output comes from a set of scattered point-light sources, neither color blends correctly, and both throw an ugly color shadow when turned up to more than about 25% intensity. This is common to LEDs in general, and is often referred to as the "disco ball effect." Because of the evenness of the distribution of the other colors in the Vertex rainbow, I do not notice this phenomena elsewhere in the fixture, but its very evident with the red and green in this module.